Abstract

We have studied the adsorption of Li atoms at the hollow sites of graphenenanoribbons (zigzag and armchair), graphene, and fullerenes by means of density functional theory calculations including local and semilocal functionals. The binding energy of a Li atom on armchair nanoribbons [of about 1.70 eV for local spin density approximation (LSDA) and 1.20 eV for Perdew–Burke–Ernzerhof (PBE)] is comparable to the corresponding value in graphene (1.55 and 1.04 eV for LSDA and PBE, respectively). Notably, the interaction between Li and zigzag nanoribbons is much stronger. The binding energy of Li at the edges of zigzag nanoribbons is about 50% stronger than in graphene for the functionals studied here. While the charge transfer between the Li adatom and the zigzag nanoribbon significantly affects the magnetic properties of the latter providing an additional interaction mechanism that is not present in a two-dimensional graphene or armchair nanoribbons, we find that the morphology of the edges, rather than magnetism, is responsible for the enhanced Li-nanoribbon interaction.

Received 14 August 2009Accepted 22 October 2009Published online 11 December 2009

Acknowledgments:

Acknowledgment is made to the donors of the American Chemical Society Petroleum Research Fund for support of this research through Award No. ACS PRF 49427-UNI6. The authors would like to acknowledge the useful comments of the anonymous referee.